/*
* ARM CMSDK APB dual-timer emulation
*
* Copyright (c) 2018 Linaro Limited
* Written by Peter Maydell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 or
* (at your option) any later version.
*/
/*
* This is a model of the "APB dual-input timer" which is part of the Cortex-M
* System Design Kit (CMSDK) and documented in the Cortex-M System
* Design Kit Technical Reference Manual (ARM DDI0479C):
* https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "trace.h"
#include "qapi/error.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
#include "hw/sysbus.h"
#include "hw/irq.h"
#include "hw/registerfields.h"
#include "hw/timer/cmsdk-apb-dualtimer.h"
REG32(TIMER1LOAD, 0x0)
REG32(TIMER1VALUE, 0x4)
REG32(TIMER1CONTROL, 0x8)
FIELD(CONTROL, ONESHOT, 0, 1)
FIELD(CONTROL, SIZE, 1, 1)
FIELD(CONTROL, PRESCALE, 2, 2)
FIELD(CONTROL, INTEN, 5, 1)
FIELD(CONTROL, MODE, 6, 1)
FIELD(CONTROL, ENABLE, 7, 1)
#define R_CONTROL_VALID_MASK (R_CONTROL_ONESHOT_MASK | R_CONTROL_SIZE_MASK | \
R_CONTROL_PRESCALE_MASK | R_CONTROL_INTEN_MASK | \
R_CONTROL_MODE_MASK | R_CONTROL_ENABLE_MASK)
REG32(TIMER1INTCLR, 0xc)
REG32(TIMER1RIS, 0x10)
REG32(TIMER1MIS, 0x14)
REG32(TIMER1BGLOAD, 0x18)
REG32(TIMER2LOAD, 0x20)
REG32(TIMER2VALUE, 0x24)
REG32(TIMER2CONTROL, 0x28)
REG32(TIMER2INTCLR, 0x2c)
REG32(TIMER2RIS, 0x30)
REG32(TIMER2MIS, 0x34)
REG32(TIMER2BGLOAD, 0x38)
REG32(TIMERITCR, 0xf00)
FIELD(TIMERITCR, ENABLE, 0, 1)
#define R_TIMERITCR_VALID_MASK R_TIMERITCR_ENABLE_MASK
REG32(TIMERITOP, 0xf04)
FIELD(TIMERITOP, TIMINT1, 0, 1)
FIELD(TIMERITOP, TIMINT2, 1, 1)
#define R_TIMERITOP_VALID_MASK (R_TIMERITOP_TIMINT1_MASK | \
R_TIMERITOP_TIMINT2_MASK)
REG32(PID4, 0xfd0)
REG32(PID5, 0xfd4)
REG32(PID6, 0xfd8)
REG32(PID7, 0xfdc)
REG32(PID0, 0xfe0)
REG32(PID1, 0xfe4)
REG32(PID2, 0xfe8)
REG32(PID3, 0xfec)
REG32(CID0, 0xff0)
REG32(CID1, 0xff4)
REG32(CID2, 0xff8)
REG32(CID3, 0xffc)
/* PID/CID values */
static const int timer_id[] = {
0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */
0x23, 0xb8, 0x1b, 0x00, /* PID0..PID3 */
0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
};
static bool cmsdk_dualtimermod_intstatus(CMSDKAPBDualTimerModule *m)
{
/* Return masked interrupt status for the timer module */
return m->intstatus && (m->control & R_CONTROL_INTEN_MASK);
}
static void cmsdk_apb_dualtimer_update(CMSDKAPBDualTimer *s)
{
bool timint1, timint2, timintc;
if (s->timeritcr) {
/* Integration test mode: outputs driven directly from TIMERITOP bits */
timint1 = s->timeritop & R_TIMERITOP_TIMINT1_MASK;
timint2 = s->timeritop & R_TIMERITOP_TIMINT2_MASK;
} else {
timint1 = cmsdk_dualtimermod_intstatus(&s->timermod[0]);
timint2 = cmsdk_dualtimermod_intstatus(&s->timermod[1]);
}
timintc = timint1 || timint2;
qemu_set_irq(s->timermod[0].timerint, timint1);
qemu_set_irq(s->timermod[1].timerint, timint2);
qemu_set_irq(s->timerintc, timintc);
}
static void cmsdk_dualtimermod_write_control(CMSDKAPBDualTimerModule *m,
uint32_t newctrl)
{
/* Handle a write to the CONTROL register */
uint32_t changed;
newctrl &= R_CONTROL_VALID_MASK;
changed = m->control ^ newctrl;
if (changed & ~newctrl & R_CONTROL_ENABLE_MASK) {
/* ENABLE cleared, stop timer before any further changes */
ptimer_stop(m->timer);
}
if (changed & R_CONTROL_PRESCALE_MASK) {
int divisor;
switch (FIELD_EX32(newctrl, CONTROL, PRESCALE)) {
case 0:
divisor = 1;
break;
case 1:
divisor = 16;
break;
case 2:
divisor = 256;
break;
case 3:
/* UNDEFINED; complain, and arbitrarily treat like 2 */
qemu_log_mask(LOG_GUEST_ERROR,
"CMSDK APB dual-timer: CONTROL.PRESCALE==0b11"
" is undefined behaviour\n");
divisor = 256;
break;
default:
g_assert_not_reached();
}
ptimer_set_freq(m->timer, m->parent->pclk_frq / divisor);
}
if (changed & R_CONTROL_MODE_MASK) {
uint32_t load;
if (newctrl & R_CONTROL_MODE_MASK) {
/* Periodic: the limit is the LOAD register value */
load = m->load;
} else {
/* Free-running: counter wraps around */
load = ptimer_get_limit(m->timer);
if (!(m->control & R_CONTROL_SIZE_MASK)) {
load = deposit32(m->load, 0, 16, load);
}
m->load = load;
load = 0xffffffff;
}
if (!(m->control & R_CONTROL_SIZE_MASK)) {
load &= 0xffff;
}
ptimer_set_limit(m->timer, load, 0);
}
if (changed & R_CONTROL_SIZE_MASK) {
/* Timer switched between 16 and 32 bit count */
uint32_t value, load;
value = ptimer_get_count(m->timer);
load = ptimer_get_limit(m->timer);
if (newctrl & R_CONTROL_SIZE_MASK) {
/* 16 -> 32, top half of VALUE is in struct field */
value = deposit32(m->value, 0, 16, value);
} else {
/* 32 -> 16: save top half to struct field and truncate */
m->value = value;
value &= 0xffff;
}
if (newctrl & R_CONTROL_MODE_MASK) {
/* Periodic, timer limit has LOAD value */
if (newctrl & R_CONTROL_SIZE_MASK) {
load = deposit32(m->load, 0, 16, load);
} else {
m->load = load;
load &= 0xffff;
}
} else {
/* Free-running, timer limit is set to give wraparound */
if (newctrl & R_CONTROL_SIZE_MASK) {
load = 0xffffffff;
} else {
load = 0xffff;
}
}
ptimer_set_count(m->timer, value);
ptimer_set_limit(m->timer, load, 0);
}
if (newctrl & R_CONTROL_ENABLE_MASK) {
/*
* ENABLE is set; start the timer after all other changes.
* We start it even if the ENABLE bit didn't actually change,
* in case the timer was an expired one-shot timer that has
* now been changed into a free-running or periodic timer.
*/
ptimer_run(m->timer, !!(newctrl & R_CONTROL_ONESHOT_MASK));
}
m->control = newctrl;
}
static uint64_t cmsdk_apb_dualtimer_read(void *opaque, hwaddr offset,
unsigned size)
{
CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(opaque);
uint64_t r;
if (offset >= A_TIMERITCR) {
switch (offset) {
case A_TIMERITCR:
r = s->timeritcr;
break;
case A_PID4 ... A_CID3:
r = timer_id[(offset - A_PID4) / 4];
break;
default:
bad_offset:
qemu_log_mask(LOG_GUEST_ERROR,
"CMSDK APB dual-timer read: bad offset %x\n",
(int) offset);
r = 0;
break;
}
} else {
int timer = offset >> 5;
CMSDKAPBDualTimerModule *m;
if (timer >= ARRAY_SIZE(s->timermod)) {
goto bad_offset;
}
m = &s->timermod[timer];
switch (offset & 0x1F) {
case A_TIMER1LOAD:
case A_TIMER1BGLOAD:
if (m->control & R_CONTROL_MODE_MASK) {
/*
* Periodic: the ptimer limit is the LOAD register value, (or
* just the low 16 bits of it if the timer is in 16-bit mode)
*/
r = ptimer_get_limit(m->timer);
if (!(m->control & R_CONTROL_SIZE_MASK)) {
r = deposit32(m->load, 0, 16, r);
}
} else {
/* Free-running: LOAD register value is just in m->load */
r = m->load;
}
break;
case A_TIMER1VALUE:
r = ptimer_get_count(m->timer);
if (!(m->control & R_CONTROL_SIZE_MASK)) {
r = deposit32(m->value, 0, 16, r);
}
break;
case A_TIMER1CONTROL:
r = m->control;
break;
case A_TIMER1RIS:
r = m->intstatus;
break;
case A_TIMER1MIS:
r = cmsdk_dualtimermod_intstatus(m);
break;
default:
goto bad_offset;
}
}
trace_cmsdk_apb_dualtimer_read(offset, r, size);
return r;
}
static void cmsdk_apb_dualtimer_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(opaque);
trace_cmsdk_apb_dualtimer_write(offset, value, size);
if (offset >= A_TIMERITCR) {
switch (offset) {
case A_TIMERITCR:
s->timeritcr = value & R_TIMERITCR_VALID_MASK;
cmsdk_apb_dualtimer_update(s);
break;
case A_TIMERITOP:
s->timeritop = value & R_TIMERITOP_VALID_MASK;
cmsdk_apb_dualtimer_update(s);
break;
default:
bad_offset:
qemu_log_mask(LOG_GUEST_ERROR,
"CMSDK APB dual-timer write: bad offset %x\n",
(int) offset);
break;
}
} else {
int timer = offset >> 5;
CMSDKAPBDualTimerModule *m;
if (timer >= ARRAY_SIZE(s->timermod)) {
goto bad_offset;
}
m = &s->timermod[timer];
switch (offset & 0x1F) {
case A_TIMER1LOAD:
/* Set the limit, and immediately reload the count from it */
m->load = value;
m->value = value;
if (!(m->control & R_CONTROL_SIZE_MASK)) {
value &= 0xffff;
}
if (!(m->control & R_CONTROL_MODE_MASK)) {
/*
* In free-running mode this won't set the limit but will
* still change the current count value.
*/
ptimer_set_count(m->timer, value);
} else {
if (!value) {
ptimer_stop(m->timer);
}
ptimer_set_limit(m->timer, value, 1);
if (value && (m->control & R_CONTROL_ENABLE_MASK)) {
/* Force possibly-expired oneshot timer to restart */
ptimer_run(m->timer, 1);
}
}
break;
case A_TIMER1BGLOAD:
/* Set the limit, but not the current count */
m->load = value;
if (!(m->control & R_CONTROL_MODE_MASK)) {
/* In free-running mode there is no limit */
break;
}
if (!(m->control & R_CONTROL_SIZE_MASK)) {
value &= 0xffff;
}
ptimer_set_limit(m->timer, value, 0);
break;
case A_TIMER1CONTROL:
cmsdk_dualtimermod_write_control(m, value);
cmsdk_apb_dualtimer_update(s);
break;
case A_TIMER1INTCLR:
m->intstatus = 0;
cmsdk_apb_dualtimer_update(s);
break;
default:
goto bad_offset;
}
}
}
static const MemoryRegionOps cmsdk_apb_dualtimer_ops = {
.read = cmsdk_apb_dualtimer_read,
.write = cmsdk_apb_dualtimer_write,
.endianness = DEVICE_LITTLE_ENDIAN,
/* byte/halfword accesses are just zero-padded on reads and writes */
.impl.min_access_size = 4,
.impl.max_access_size = 4,
.valid.min_access_size = 1,
.valid.max_access_size = 4,
};
static void cmsdk_dualtimermod_tick(void *opaque)
{
CMSDKAPBDualTimerModule *m = opaque;
m->intstatus = 1;
cmsdk_apb_dualtimer_update(m->parent);
}
static void cmsdk_dualtimermod_reset(CMSDKAPBDualTimerModule *m)
{
m->control = R_CONTROL_INTEN_MASK;
m->intstatus = 0;
m->load = 0;
m->value = 0xffffffff;
ptimer_stop(m->timer);
/*
* We start in free-running mode, with VALUE at 0xffffffff, and
* in 16-bit counter mode. This means that the ptimer count and
* limit must both be set to 0xffff, so we wrap at 16 bits.
*/
ptimer_set_limit(m->timer, 0xffff, 1);
ptimer_set_freq(m->timer, m->parent->pclk_frq);
}
static void cmsdk_apb_dualtimer_reset(DeviceState *dev)
{
CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(dev);
int i;
trace_cmsdk_apb_dualtimer_reset();
for (i = 0; i < ARRAY_SIZE(s->timermod); i++) {
cmsdk_dualtimermod_reset(&s->timermod[i]);
}
s->timeritcr = 0;
s->timeritop = 0;
}
static void cmsdk_apb_dualtimer_init(Object *obj)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(obj);
int i;
memory_region_init_io(&s->iomem, obj, &cmsdk_apb_dualtimer_ops,
s, "cmsdk-apb-dualtimer", 0x1000);
sysbus_init_mmio(sbd, &s->iomem);
sysbus_init_irq(sbd, &s->timerintc);
for (i = 0; i < ARRAY_SIZE(s->timermod); i++) {
sysbus_init_irq(sbd, &s->timermod[i].timerint);
}
}
static void cmsdk_apb_dualtimer_realize(DeviceState *dev, Error **errp)
{
CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(dev);
int i;
if (s->pclk_frq == 0) {
error_setg(errp, "CMSDK APB timer: pclk-frq property must be set");
return;
}
for (i = 0; i < ARRAY_SIZE(s->timermod); i++) {
CMSDKAPBDualTimerModule *m = &s->timermod[i];
QEMUBH *bh = qemu_bh_new(cmsdk_dualtimermod_tick, m);
m->parent = s;
m->timer = ptimer_init(bh,
PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD |
PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT |
PTIMER_POLICY_NO_IMMEDIATE_RELOAD |
PTIMER_POLICY_NO_COUNTER_ROUND_DOWN);
}
}
static const VMStateDescription cmsdk_dualtimermod_vmstate = {
.name = "cmsdk-apb-dualtimer-module",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_PTIMER(timer, CMSDKAPBDualTimerModule),
VMSTATE_UINT32(load, CMSDKAPBDualTimerModule),
VMSTATE_UINT32(value, CMSDKAPBDualTimerModule),
VMSTATE_UINT32(control, CMSDKAPBDualTimerModule),
VMSTATE_UINT32(intstatus, CMSDKAPBDualTimerModule),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription cmsdk_apb_dualtimer_vmstate = {
.name = "cmsdk-apb-dualtimer",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_STRUCT_ARRAY(timermod, CMSDKAPBDualTimer,
CMSDK_APB_DUALTIMER_NUM_MODULES,
1, cmsdk_dualtimermod_vmstate,
CMSDKAPBDualTimerModule),
VMSTATE_UINT32(timeritcr, CMSDKAPBDualTimer),
VMSTATE_UINT32(timeritop, CMSDKAPBDualTimer),
VMSTATE_END_OF_LIST()
}
};
static Property cmsdk_apb_dualtimer_properties[] = {
DEFINE_PROP_UINT32("pclk-frq", CMSDKAPBDualTimer, pclk_frq, 0),
DEFINE_PROP_END_OF_LIST(),
};
static void cmsdk_apb_dualtimer_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = cmsdk_apb_dualtimer_realize;
dc->vmsd = &cmsdk_apb_dualtimer_vmstate;
dc->reset = cmsdk_apb_dualtimer_reset;
dc->props = cmsdk_apb_dualtimer_properties;
}
static const TypeInfo cmsdk_apb_dualtimer_info = {
.name = TYPE_CMSDK_APB_DUALTIMER,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(CMSDKAPBDualTimer),
.instance_init = cmsdk_apb_dualtimer_init,
.class_init = cmsdk_apb_dualtimer_class_init,
};
static void cmsdk_apb_dualtimer_register_types(void)
{
type_register_static(&cmsdk_apb_dualtimer_info);
}
type_init(cmsdk_apb_dualtimer_register_types);
